(http://www.crossingpoint.za.net/quadx/pre%20midi%20schematics/symbol.gif)
any help appreciated.
those 'tag' looking things are usually a connection to another circuit on another board, though the V- seems to imply a negative voltage rail.. but it might not be, because what is the flyspeck beside it??! my 2c anyway!
there seems to be a speck to the left as well - it looks like they emphasize it's a label by putting it down as "V-"
there might be more of those in the schem, plus one with the arrowhead of the tag pointing out of circuit instead of in. That last one is the V- rail, all points labbed accordingly connect to that.
there's another 2 points on the board with that 'tag' (looks like an exponential 1 or something)
(http://www.crossingpoint.za.net/quadx/pre%20midi%20schematics/symbol2.gif)
Any other ideas?
looking at the little thing on the right, V- connects to some sort of voltage regulation circuit. As they show, it represents a logic 0.
darn Im sure one of you guys would be able to help me with this thread
then...?
http://diystompboxes.com/sboxforum/viewtopic.php?t=22055
take a look at the full circuit:
http://www.crossingpoint.za.net/quadx/pre%20midi%20schematics/8400114_C_G_small.gif
there is probably a nohter drawing for the power supply. it would probably be a lot more obvious if you had that drawing. V- is probably just ground, but they dont want to show it that way, because they dont want it to be chassis ground. also depending on the way the power supply is set up they may infact have a dual polarity supply.
I'm not sure if u realize this, but all this schematic is is a switching unit. I'm pretty sure the effects ins come from that "D-Connector" at the bottom left. The rest is just midi switching.
There _should_ be more to the schematic.
that circuit has over 160 resistors!!!!!!!!!!!!!!!!
Yes, it's definitely a supply voltage rail: as even more evidence, take a look at the 16-pin IC (the 4017) at the top. V+ is tied to ground and the V- on the chip goes to the V- rail (or regulator circuit).
wow, thanks for the great feedback.
This is one of 9 pages of schematic. But this one deals with the SWITCHING part of it. The rest is for the actual amp stuff.
The D9 connector in lower left is for the footswitch to plugin. that has 7 momentary switches on it and a bunch more internal circuitry (I have the schematic for that too)
The jack plugs down the left hand side which Im trying to switch, do the same function as the D9, but are meant to interface with something else.
Im trying to work out WHAT that something else is, first step is to find out what those jack plugs NEED to switch. touching to ground switches ON in all cases, but I cant work out how to toggle the lower 3 ON and OFF, which is why Im asking about that V- voltage in the top right (cos that part of the circuit deals with toggling these 3 channels ON/OFF). Do I need to supply a negative voltage to get the circuit to switch that channel OFF!?
Brian, the power supply schematic:
http://www.crossingpoint.za.net/quadx/pre%20midi%20schematics/8400108_C_E.gif
Any other ideas?
does that funny looking '1' tag not mean V- inverted??
Maybe there are separate V- supplies for analog and digital?
I've never personally seen that, but anythign is possible in a mixed signal thing like this!
My guess is it's V-'.
The primed simply means it's another rail at or near V- potential. If it's a V- with a superscipt one then the same meaning would apply (and I can't see a Note #1 that makes sense regarding that rail).
It's either connected directly to V- on a particular track (for the LEDs only?), or it goes to a filtered rail. It only goes to the LED so it's something particular about those (maybe even switched). As far as the circuit functioning goes, V-' might as well be V-.
Oh btw thats the symbol for digital I/O, meaning that those connect to a DSP (if it's audio) and there would be pin markings next to it. Thats the explanation I came up with.